python之字符串详解2

逻辑判断字符串类型，返回布尔值

1. islower

描述：判断所有字符是否为小写

语法：

    def islower(self): # real signature unknown; restored from __doc__
        """
        S.islower() -> bool
        
        Return True if all cased characters in S are lowercase and there is
        at least one cased character in S, False otherwise.
        """
        return False

样例：

name='allen'
result=name.islower()    #判断字符都为小写
print(result)

True    #显示结果

2. isupper

描述：判断所有字符是否为大写

语法：

    def isupper(self): # real signature unknown; restored from __doc__
        """
        S.isupper() -> bool
        
        Return True if all cased characters in S are uppercase and there is
        at least one cased character in S, False otherwise.
        """
        return False

样例：

name='allen'
result=name.isupper()    #判断所有字符为大写
print(result)

False    #显示结果

3. istitle

描述：判断是否为title类型，即第一个字符为大写，其他为小写

语法：

    def istitle(self): # real signature unknown; restored from __doc__
        """
        S.istitle() -> bool
        
        Return True if S is a titlecased string and there is at least one
        character in S, i.e. upper- and titlecase characters may only
        follow uncased characters and lowercase characters only cased ones.
        Return False otherwise.
        """
        return False

样例：

name='Allen'
result=name.istitle()    #判断是否为title类型的字符串
print(result)

True    #显示结果

4. isalpha

描述：判断所有字符是否为字母

语法：

  def isalnum(self): # real signature unknown; restored from __doc__
        """
        S.isalnum() -> bool
        
        Return True if all characters in S are alphanumeric
        and there is at least one character in S, False otherwise.
        """
        return False

样例：

name = 'allen'
result=name.isalpha()    #判断所有字符为字母
print(result)

True    #显示结果

5. isdigit

描述：判断所有字符是否为数字

语法：

    def isdigit(self): # real signature unknown; restored from __doc__
        """
        S.isdigit() -> bool
        
        Return True if all characters in S are digits
        and there is at least one character in S, False otherwise.
        """
        return False

样例：

name = '123'
result=name.isdigit()    #判断所有字符为数字
print(result)

True    #显示结果

name = '123abc'
result=name.isdigit()    #判断所有字符为数字
print(result)

False   #显示结果

6. isdecimal

描述：判断所有字符是否是十进制数

语法：

    def isdecimal(self): # real signature unknown; restored from __doc__
        """
        S.isdecimal() -> bool
        
        Return True if there are only decimal characters in S,
        False otherwise.
        """
        return False

样例：

name = '123'
result=name.isdecimal()    #判断所有字符是否是十进制
print(result)

True    #显示结果


name = '123abc'
result=name.isdecimal()    #判断所有字符是否是十进制
print(result)

False    #显示结果